Furniture leg



Dec. 5, 1967 K. D. SCHREYER ETAL 3,

FURNITURE LEG Filed March 18, 1966 2 Sheets-Sheet 1 INVENTORS KENNETH D. SCHREYER EDWARD C. STEWART ATTORNEYS United States Patent 3,356,327 FURNITURE LEG Kenneth D. Schreyer, Doylestown, Pa., and Edward C. Stewart, Aurora, 111., assignors to Lyon Metal Products, Incorporated, Aurora, 111., a corporation of Illinois Filed Mar. 18, 1966, Ser. No. 535,421 17 Claims. (Cl. 248188.4)

The present invention relates to an adjustable foot assembly for use on the bottom of a leg for furniture and the like, and to an assembly of such an adjustable foot with a furniture leg.

It is an important object of the present invention to provide an adjustable foot assembly including a thimble for mounting on the lower end of an associated leg and a foot longitudinally adjustable with respect to the thimble and thus with respect to the leg, thereby adjustably to change the effective length of the leg and foot assembly as desired.

Another object of the invention is to provide an adjustable foot assembly of the type set forth wherein a positive alignment of the foot with the leg is obtained in all adjusted positions of the foot with respect to the leg.

Yet another object of the invention is to provide an adjustable foot assembly of the type set forth including mechanism that permits ready stepwise adjustment of the longitudinal position of the foot with respect to the leg while always maintaining the rotational alignment between the foot and the leg after adjustment therebetween.

In connection with the foregoing object, another object of the invention isto provide an adjustable foot assembly of the type set forth wherein the adjustment between the foot and the leg is maintained even when the furniture leg is lifted from the floor so that the foot is out of engagement with the floor or any other support structure.

A further object of the invention is to provide an adjustable foot assembly of the type set forth which is rugged in construction, yet economical in manufacture.

A still further object of the invention is to provide the combination of a leg with an adjustable foot assembly of the type set forth.

Further features of the invention pertain to the particular arrangement and construction of the parts whereby the above-outlined and additional operating features thereof are attained.

The invention, both as to its organization and method of operation, together with further objects and advantages thereof, will best be understood by reference to the following specification taken in connection with the accompanying drawings, in which:

FIGURE 1 is a perspective view of a desk having thereon legs provided at the lower ends thereof with an adjustable foot assembly made in accordance with and embodying the principles of the present invention;

FIG. 2 is an enlarged fragmentary side elevational view of the lower end of one of the legs of FIG. 1;

FIG. 3 is a view similar to FIG. 2 with the portion of the wall of the leg removed and with the foot partially withdrawn from the leg and the associated thimble prior to changing the adjustment between the foot and the leg;

FIG. 4 is a view similar to FIG. 3 illustrating the foot in an impartially turned position during the adjustment of the position thereof with respect to the associated leg;

FIG. 5 is a view in horizontal section along the line 5-5 of FIG. 2;

FIG. 6 is a plan view of the foot assembly of FIGS. 2 to 4 with the leg removed therefrom, the view being on a slightly enlarged scale;

FIG. 7 is a view in vertical section through the foot assembly of FIG. 6 along the line 77 thereof;

. FIG. 8. is a view in horizontal section along the line 8-8 of FIG. 7; and

FIG. 9 is a view in horizontal section along the line 99 of FIG. 7.

There is illustrated in FIG. 1 of the drawings a desk 10 equipped with an adjustable foot assembly made in accordance with and embodying the principles of the present invention. It will be understood that the desk 10 is simply illustrative of a piece of furniture on which the adjustable foot assembly 100 of the present invention is useful. As illustrated, the desk 10 includes the usual desk top 11, a pedestal 12 disposed at one end of the desk top 11, an end wall 17 disposed at the other end thereof and a rear wall 18 interconnecting the pedestal-12 and the end wall 17 at the rear edge of the desk top 11. The pedestal 12 is provided with the usual drawers 13 and 14 having pulls 15 and 16, respectively, thereon.

At each of the four corners of the desk 10 there is provided a leg 20 arranged substantially vertically and connected to the adjacent desk parts and carrying on the lower end thereof one of the adjustable foot assemblies 100. Each of the legs 20 is hollow in construction and is formed by bending sheet metal into a configuration that is square in cross section formed by four mutually perpendicular walls 21 joined to each other to provide a rigid strong construction. The lower ends of each of the walls 21 terminate in the lower edges 22 disposed in a plane normal to the longitudinal axis of the leg 20. As best shown in FIG. 3, the adjustable foot assembly 100 is carried by and extends into the lower end of the associated leg 20.

The foot assembly 100 includes generally a foot 101, a thimble 120, a nut 140, a washer 150 and a spring 160. Referring particularly to FIGS. 6 to 9 of the drawings, it will be seen that the foot 101 includes a base 102 that is essentially square in horizontal section and includes a bottom wall 103 adapted to rest upon an underlying support surface such as a floor and integral side walls 104 extending upwardly from the bottom wall 103, four of the side walls 104 being provided arranged mutually perpendicular to provide a square peripheral shape for the base 102. Integral with the base 102 and extending upwardly therefrom is a body 105 that'is also generally square in cross section (see FIG. 9) but has a smaller cross section than the associated base 102, whereby a top wall 106 is provided on top of the base 102 extending outwardly from the body 105. The body 105 is provided with four side walls 107 arranged mutually perpendicular to provide an essentially square peripheral shape for the body 105, the longitudinal axis of the body 105 being in alignment with the longitudinal axis of the base 102 and with the side walls 107 set inwardly from the side walls 104. The upper portion of the body 105 has a shoulder 108 thereon and extending upwardly therefrom and in general axial alignment therewith is a shank 110. As illustrated, the shank 110 has a pair of parallel opposed flat sides 116 that extend upwardly through the associated nut 140 and through the upper end of the thimble 120, a threaded portion 111 being provided on the shank, the longitudinal extent of the threaded portion 111 being essentially the same as the longitudinal extent of the flat sides 116. The upper end of the shank 110 carries a tapered portion 112 that terminates in a shoulder 113 at the juncture with a reduced portion 114. As illustrated, the reduced portion 114 is upset or peened over to provide a locking portion 115 to hold the Washer 150 in position on the shoulder 113, all as will be explained more fully hereinafter.

The thimble includes a generally cylindrical hollow shell 121 having a generally square shaped exterior (see FIG. 6) and having a generally square shaped recess therein so as to receive the square shaped body 105 on the foot 101. The lower end of the thimble 120 has an outwardly extending base 122 thereon, the base 122 having. fourouter side walls 123 arranged mutually perpendicular to each other and having the same length as the side walls 104 on the foot 101 and also the same length as the width of the associated side of the leg 20, as will be explained more fully hereinafter. Formed on the upper side of the base 122 is a shoulder 125 that bears against the lower end of the associated leg 20 and joins four vertically extending upper side walls 126 disposed mutually perpendicular one to the other and generally square in cross section as may be best seen in FIGS. 6 and 8. Extending laterally outwardly from each of the side walls 126 is a pair of spaced apart fins 127 that converge to a sharp edge, the fins 127 being forced into the material of the associated leg 20, thereby fixedly to mount the thimble 120 within the associated hollow leg 20. The shoulder 125 on the thimble 120 contains a concave pocket 128 for a fine line contact and for receiving shavings produced as a result of the insertion of the thimble 120 into the associated leg 20.

The interior of the thimble 120 is formed hollow and shaped generally square and is provided with four inner side walls 130 disposed mutually perpendicular and having transverse dimensions slightly greater than the transverse dimensions of the side walls 107 on the foot 101, whereby to receive the body 105 of the foot 101 within the thimble 120 as is best illustrated in FIG. 7. The upper end of the thimble 120 has an inwardly directed top wall 131 thereon that partially closes the upper end of the thimble 120 and is provided centrally thereof with an opening 132 for receiving the upper end of the shank 110 therethrough. There is provided on the upper end of the thimble 120 at the top wall 131 and on the exterior thereof a shoulder 133 for engaging the lower end of the spring 160, as will be explained more fully hereinafter, and there is provided on the top wall 131 interiorly of the thimble 120 an underside 134 for engagement with the nut 140, as will also be explained more fully hereinafter.

Disposed about the threaded portion 111 of the shank 110 is the nut 140, the nut 140 being internally threaded as at 141 and having four outer walls 142 arranged mutually perpendicular so as to provide a square cross section (see FIG. 8), the lengths of the walls 142 being slightly less than the lengths of the walls 130, whereby the nut 140 fits within the recess in the thimble 120. The nut 140 further has a top wall 143 and a bottom wall 144 arranged essentially parallel to each other and mutually perpendicular to the outer walls 142, the top wall 143 normally bearing against the underside 134 of the top wall 131 on the thimble 120.

In order to retain the various parts of the adjustable foot assembly in an assembled condition, the washer 150 and the spring 160 have been provided. The washer 150 is formed fiat, having generally parallel upper and lower surfaces 151 and 152, respectively, and having an opening 153 centrally therein receiving therethrough the reduced portion 114 on the shank 110, the locking portion 115 holding the washer 150 upon the shoulder 113 of the shank 110. Disposed between the thimble 120, and specifically the top wall 131 thereof, and the washer 150 is the spring 160, the spring 160 being tapered upwardly and having a lowermost coil 161 disposed on the shoulder 133 and centered by a ring 135 carried by the top wall 131 and an uppermost coil 162 disposed about the upper end of the shank 110 and bearing against the lower surface 152 of the washer 150. The spring 160 is under compression in all the adjusted positions of the parts, thereby continually to urge the shank 110 and the associated parts upwardly and thereby to urge the nut 140 continually toward the underside 134 of the top wall 131. However, the spring 160 can be compressed by pulling the foot 101 downwardly to move the parts to the position illustrated in FIG. 3, after which the foot and attached portions can be rotated about the longitudinal axis thereof to cause the adjustment of the position of the nut 140 along the shank 110 as will be described more fully hereinafter. In the assembly of the washer 150 and the spring 160 with the other parts, the spring 160 is first placed in position prior to deformation of the reduced portion 114, after which the washer 150 is slipped over the outer end of the reduced portion 114 (it being understood that the reduced portion 114 originally was essentially cylindrical). The outer end of the reduced portion 114 is then riveted, spun, staked or peened over to provide the locking portion 115 which has a diameter greater than the diameter of the opening 153 in the Washer 150, thereby to hold the washer 150 firmly upon the shoulder 113 of the shank 110, and also to trap the spring 160 between the shoulder 133 on the thimble and the lower surface 152 on the washer 150.

The thus completed foot assembly 100 is readily and simply mounted upon the lower end of the associated leg 20. More specifically, it will be seen that the upper ends of the fins 127 are cut away or tapered as at 129, thus facilitating initial entry of the thimble 120 into the lower end of the associated leg 20. Sulficient driving force is then applied to move the thimble upwardly into the leg 20, the fins 127 digging into the material of the leg walls 21 as required to accommodate the relative movement between the thimble 120 and the leg 20. After the application of sufiicient driving force, the lower edges 22 of the leg 20 are firmly seated upon the shoulders of the thimble 120, any material such as shavings or the like gouged from the inner surfaces of the leg 20 being accommodated by the pockets 128 in the base 122. As may be best seen in FIG. 2 the lower edges 22 firmly seat against the shoulders 125 to form a good fit therebetween that is essentially but a single line. It will be seen that the lateral dimension of each of the leg side walls 21 is equal to the lateral dimensions of each of the thimble side walls 123, whereby the thimble base 122 appears to be simply an elongation or extension of the associated leg 20. Likewise, the lateral dimension of the foot base 102 is also equal to the lateral dimensions of the leg side walls 21 as well as the thimble base 122, whereby the foot base 102 likewise appears to be but a continuation of the lower end of the leg 20.

In accordance with the present invention, the longitudinal position between the foot base 102 and the thimble base 122, and those between the foot base 102 and the leg 20 can be readily adjusted, and once adjusted, the adjustment is maintained until a new adjustment is purposefully made. In order to adjust the position of the foot 100 with respect to the leg 20, the foot 100 is grasped as by the base 102 thereof and pulled downwardly to the position illustrated in FIG. 3, i.e., until the body 105 clears the lower edge of the thimble base 122. With the parts in this position, the foot 101 can be rotated about its longitudinal axis thereby to thread the shank 110 into and out of the nut 140. During such adjustment, the thimble 120, and specifically the side walls 130 thereof, engage the side walls 142 of the nut to limit rotation therebetween, thereby permitting the shank 110 to be threaded through the nut 140. FIG. 4 illustrated an intermediate position of the foot 101 during an adjustment operation; however, it will be understood that the body 105 must be placed into registration with the square recess in the thimble 120 before the foot 101 can be returned to the operative position thereof.

Recapitulating, by pulling the foot 101 downwardly against the action of the spring to remove the body 105 from the thimble 120 while rotating the nut 140 therein, the foot 101 can be turned about its longitudinal axis to thread the nut 140 upwardly and downwardly along the shank 110. If the nut 140 is moved upwardly along the shank 110 as viewed in FIG. 7, then upon returning the parts to the operative position, the foot 101, and specifically the bottom wall 103 thereof, will be disposed in a lower position with respect to the leg 20, thus effectively to lengthen the associated leg 20. Conversely, if the nut 140 is threaded downwardly with respect to the shank 110 as viewed in FIG. 7, then the bottom wall 103 of the foot 101 will be moved upwardly relative to the leg 20 when the parts are returned to the operative position, thereby effectively to shorten the length of the associated leg 20. In the operative position of the parts illustrated in FIG. 7, the load of the desk is transmitted downwardly through the leg 20 onto the thimble 120 through the shoulder 125 thereon and thence downwardly through the nut 140 to the shank 110 and thus through the foot 101 to the bottom wall 103 thereof.

Once the foot assembly 100is in an adjusted position thereof, it will be retained in that adjusted position until purposefully changed to some other adjusted position. More specifically, the interference between the body 105 of the foot 101 and the interior of the thimble 120' positively prevents rotation or adjustment among the parts when they are in the operative position illustrated in FIG. 7. Furthermore, the parts are maintained in this operative position with respect to each other and with respect to the leg 20 by the action of the spring 160, whereby it requires a purposeful pulling of the foot 101 downwardly to the position illustrated in FIG. 3 before any adjustment of the parts can be made. As a consequence, the desk can be lifted and otherwise shifted and moved without disturbing the adjustment of the foot assemblies 100. In addition, this interference between the body 105 with the foot 101 and the inner walls 130 of the thimble 120 serves to provide positive alignment of the foot 101 with respect to the leg 20, as will be readily appreciated. Furthermore, the adjustment of the foot 101 with respect to the leg is stepwise in relatively small increments, thereby to provide a large number of adjusted positions throughout a substantial range of adjustment as determined by the vertical extent of the body 105, i.e., by the vertical distance between the top wall 106 and the shoulder 108 thereof. 1

The spring 160 is further constructed such that it is fully compressed and is in a rigid condition when the nut 140 is still in engagement with the thread on the threaded portion 111 of the shank 110. As a consequence, the shank 110 can never be fully withdrawn from the nut 140 and, accordingly, the parts are maintained in the assembled condition in all adjusted positions thereof. This construction in effect provides a stop position for the parts when the foot is in the full out adjusted position with all of the parts still assembled and cooperating.

The foot assembly 100 is of unusually strong construction, the foot 101 being integral and of tapered pyramidal structure, whereas the thimble 120 is of cylindrical structure, both of which shapes are fundamentally structurally strong. The parts are all preferably formed of metal and those parts exposed to view can be chromium plated or otherwise decorated as desired.

While there has been described what is at present considered to be the preferred embodiment of the invention, it will be understood that various modifications may be made therein, and it is intended to cover in the appended claims all such modifications as fall within the true spirit and scope of the invention.

What is claimed is:

1. An adjustable foot assembly for use on the bottom of a leg for furniture and the like comprising a thimble including a hollow shell for mounting on the lower end of an associated leg and a top wall closing one end of said shell and having an opening therein, a foot including a body normally disposed within said shell and a base on one end of said body extending outwardly beyond the other end of said shell and a threaded shank on the other end of said body and extending through said opening in said shell, a nut mounted on said threaded shank for threaded movement therealong and normally disposed within said shell, and means preventing separation of said foot from said thimble, the inner periphery of said shell being non-circular and the outer periphery of said nut being shaped complementary thereto, whereby rotation of said shank about the longitudinal axis thereof moves said nut longitudinally therealong due to the interfering contact between said shell and said nut, the outer periphery of said body also being shaped complementary to the inner periphery of said shell, thereby to hold said foot and said thimble in the adjusted longitudinal position with respect to each other when said body is in the normal position thereof within said shell, said'foot being longitudinally shiftable to remove said body from said shell to permit rotation of said shaft with respect to said nut While said nut is held by said shell thus to adjust the longitudinal position of said nut along said shank and consequently to adjust the longitudinal position of said foot with respect to said thimble upon the return of said body to the normal position thereof in said shell and the return of said nut against said top wall.

2. The adjustable foot assembly set forth in claim 1, wherein both the outer periphery of said body and inner periphery of said shell are in the form of a regular noncircular geometric shape.

3. The adjustable foot assembly set forth in claim 1, wherein both the outer periphery of said body and inner periphery of said shell are square.

4. The adjustable foot assembly set forth in claim 1, wherein said means preventing separation of said foot from said thimble comprises a washer carried by the outer end of said shank disposed beyond said one end of said shell.

5. The adjustable foot assembly set forth in claim 1, and further comprising structure on said shell for mounting said foot assembly within the lower end of an associated leg.

6. The adjustable foot assembly set forth in claim 1, and further comprising a plurality of longitudinally outwardly extending fins on the exterior of said shell for engagement with an associated leg to mount said foot assembly thereon.

7. An adjustable foot assembly for use on the bottom of a leg for furniture and the like comprising a thimble including a hollow shell for mounting on the lower end of an associated leg and a top wall closing one end of said shell and having an opening therein, a foot including a body normally disposed within said shell and a base on one end of said body extending outwardly beyond the other end of said shell and a threaded shank on the other end of said body and extending through said opening in said shell, a nut mounted on said threaded shank for threaded movement therealong and normally disposed within said shell, and means acting between said thimble and said foot resiliently urging said body and said nut into said shell and resiliently urging said nut against said top wall, the inner periphery of said shell being non-circular and the outer periphery of said nut being shaped complementary thereto, whereby rotation of said shank about the longitudinal axis thereof moves said nut longitudinally therealong due to the interfering contact between said shell and said nut, the outer periphcry of said body also being shaped complementary to the inner periphery of said shell, thereby to hold said foot and said thimble in the adjusted longitudinal position with respect to each other when said body is held in the normal position thereof within said shell by said resilient means, said foot being longitudinally shiftable against the action of said resilient means to remove said body from said shell to permit rotation of said shaft with respect to said nut while said nut is held by said shell thus to adjust the longitudinal poistion of said nut along said shank and consequently to adjust the longitudinal position of said foot with respect to said thimble upon the return of said body to the normal position thereof in said shell and the return of said nut against said top wall under the urging of said resilient means.

8. The adjust-able foot assembly set forth in claim 7, and further comprising a washer mounted on the outer end of said shank and disposed outwardly with respect to said one end of said thimble, and said resilient means is a spring under compression disposed between said washer and said one end of said shell.

9. The adjustable foot assembly set forth in claim 8, wherein said spring is in the fully compressed and rigid condition when said foot is in the full out adjusted position and still in engagement with said nut.

10. The adjustable foot assembly set forth in claim 7, and further cOmprising a base on the lower end of said shell extending laterally therefrom, and a base at the lower end of said body extending laterally therefrom, said bases having the same peripheral shape, whereby said bases are in alignment with each other when said thimble and said foot are in the normal adjusted position with respect to each other.

11. An adjustable foot assembly for use on the bottom of a leg for furniture and the like comprising a thimble including a hollow shell for mounting on the lower end of an associated leg and a top wall closing one end of said shell and having an opening therein, a foot including a body normally disposed within said shell and a base on one end of said body extending outwardly beyond the other end of said shell and a threaded shank on the other end of said body and extending through said opening in said shell, a nut mounted on said threaded shank for threaded movement therealong and normally disposed within said shell, a washer mounted on the outer end of said shank and disposed outwardly with respect to said one end of said shell, and a spring disposed between said washer and said one end of said shell and continually ur-ging said nut into engagement with said top wall, the inner periphery of said shell being substantially square in shape and the outer periphery of said nut being substantially square in shape and only slightly smaller than the inner periphery of said shell whereby rotation of said shank about the longitudinal axis thereof moves said nut longitudinally therealong due to the interfering contact between the peripheries of said shell and said nut, the outer periphcry of said body also being shaped substantially square and only slightly smaller than the inner periphery of said shell, thereby to hold said foot and said thimble in the adjusted longitudinal position with respect to each other when said body is held in the normal position thereof Within said shell by said spring, said foot being longitudinally shiftable against the action of said spring to remove said body from said shell to permit rotation of said shaft with respect to said nut while said nut is held by said shell thus to adjust the longitudinal position of said nut along said shank and consequently to adjust the longitudinal position of said foot with respect to said thimble upon the return of said body to the normal position thereof in said shell and the return of said nut against said top wall under the urging of said spring.

12. A leg and adjustable foot assembly for furniture and the like comprising a leg having a recess in the lower end thereof defined by a peripheral wall, a thimble including a hollow cylindrical shell disposed in said recess and a top wall closing one end of said shell and having an opening therein, a foot including a body normally disposed within said shell and a base on one end of said body extending outwardly beyond the other end of said shell and a threaded shank on the other end of said body and extending through said opening in said shell, a nut mounted on said threaded shank for threaded movement therealong and normally disposed within said shell, and means preventing separation of said foot from said thimble,

the inner periphery of said shell being non-circular and the outer periphery of said nut being shaped complementary thereto, whereby rotation of said shank about the longitudinal axis thereof moves said nut longitudinally therealong due to the interfering contact between said shell and said mm, the outer periphery of said body also being shaped complementary to the inner periphery of said shell, thereby to hold said foot and said thimble in the adjusted longitudinal position with respect to each other when said body is in the normal position thereof Within said shell, said foot being longitudinally shiftable to remove said body from said shell to permit rotation of said shaft with respect to said nut while said nut is held by said shell thus to adjust the longitudinal position of said nut along said shank and consequently to adjust the longitudinal position of said foot with respect to said thimble upon the return of said body to the normal position thereof in said shell and the return of said nut against said top wall.

13. The leg and adjustable foot assembly of claim 12, and further comprising a plurality of longitudinal fins on the exterior of said shell and extending outwardly therefrom and engaging the inner wall defining the recess in said leg firmly to mount said shell and associated parts in said leg.

14. The leg and adjustable foot assembly set forth in claim 13, and further comprising a base on the lower end of said shell extending outwardly therefrom and underlying the lower end of said leg, the upper portion of said base having a shavings pocket therein to receive material gouged from said leg upon the insertion of said fins thereinto and to provide a line fit with the bottom of said leg.

15. The leg and adjustable foot assembly of claim 12, and further comprising a base on the lower portion of said body and extending laterally therefrom and underlying the lower end of said leg, the outer periphery of said base and the outer periphery of said leg having the same peripheral shape.

16. The leg and adjustable foot assembly of claim 12, and further comprising a first base on the lower end of said shell extending laterally therefrom and being disposed immediately beneath the lower end of said leg, a second base on the lower end of said body and extending laterally outwardly therefrom and underlying said first base, the outer periphery of said leg and the outer periphery of said first base the outer periphery of said second base all having the same shape.

17. The leg and adjustable foot assembly set forth in claim 15, wherein the peripheral shape of said leg and said first base and said second base is essentially square.

References Cited UNITED STATES PATENTS 2,295,911 9/1942 Page 248-1884 X 2,465,742 3/1942 Nalle 248l88.4 X 2,850,309 9/1958 Grover 248-1884 X FOREIGN PATENTS 962,929 7/ 1964 Great Britain.

CHANCELLOR E. HARRIS, Primary Examiner, 

1. AN ADJUSTABLE FOOT ASSEMBLY FOR USE ON THE BOTTOM OF A LEG FOR FURNITURE AND THE LIKE COMPRISING A THIMBLE INCLUDING A HOLLOW SHELL FOR MOUNTING ON THE LOWER END OF AN ASSOCIATED LEG AND A TOP WALL CLOSING ONE END OF SAID SHELL AND HAVING AN OPENING THEREIN, A FOOT INCLUDING A BODY NORMALLY DISPOSED WITHIN SAID SHELL AND A BASE ON ONE END OF SAID BODY EXTENDING OUTWARDLY BEYOND THE OTHER END OF SAID SHELL AND A THREADED SHANK ON THE OTHER END OF SAID BODY AND EXTENDING THROUGH SAID OPENING IN SAID SHELL, A NUT MOUNTED ON SAID THREADED SHANK FOR THREADED MOVEMENT THEREALONG AND NORMALLY DISPOSED WITHIN SAID SHELL, AND MEANS PREVENTING SEPARATION OF SAID FOOT FROM SAID THIMBLE, THE INNER PERIPHERY OF SAID SHELL BEING NON-CIRCULAR AND THE OUTER PERIPHERY OF SAID NUT BEING SHAPED COMPLEMENTARY THERETO, WHEREBY ROTATION OF SAID SHANK ABOUT THE LONGITUDINAL AXIS THEREOF MOVES SAID NUT LONGITUDINALLY THEREALONG DUE TO THE INTERFERING CONTACT BETWEEN SAID SHEEL AND SAID NUT, THE OUTER PERIPHERY OF SAID BODY ALSO BEING SHAPED COMPLEMENTARY TO THE INNER PERIPHERY OF SAID SHELL, THEREBY TO HOLD SAID FOOT AND SAID THIMBLE IN THE ADJUSTED LONGITUDINAL POSITION WITH RESPECT TO EACH OTHER WHEN SAID BODY IS IN THE NORMAL POSITION THEREOF WITHIN SAID SHELL, SAID FOOT BEING LONGITUDINALLY SHIFTABLE TO REMOVE SAID BODY FROM SAID SHELL TO PERMIT ROTATION OF SAID SHAFT WIH RESPECT TO SAID NUT WHILE SAID NUT IS HELD BY SAID SHELL THUS TO ADJUST THE LONGITUDINAL POSITION OF SAID NUT ALONG SAID SHANK AND CONSEQUENTLY TO ADJUST THE LONGITUDINAL POSITION OF SAID FOOT WITH RESPECT TO SAID THIMBLE UPON THE RETURN OF SAID BODY OF TO THE NORMAL POSITION THEREOF IN SAID SHELL AND THE RETURN OF SAID NUT AGAINST SAID TOP WALL. 